Mathematics
Every solver below shows its working, free — the step-by-step other sites charge for. Pick a topic, type your question, and check the answer backwards.
All mathematics calculators
✓Math Solver
Type an equation or a plain sum. You get the answer and every step, free — the steps other sites lock behind a subscription.∫Integral Calculator
Type a function. You get its indefinite integral and the rule used on every term.∂Derivative Calculator
Type a function. You get its derivative and the rule used on every term.limLimit Calculator
Type a function and the point it approaches. You get the limit and how it was found — by substitution when that works, from both sides when it does not.×Factor Calculator
Type a whole number or a quadratic. You get its factors and the divisions that found them.≡Simplify Calculator
Type an expression. You get its simplest form, and a same-value check at real numbers.⧉System of Equations Solver
Type two or three linear equations. You get the values that satisfy all of them at once, found with Cramer's rule.▦Matrix Calculator
Type a matrix. You get its determinant, inverse or eigenvalues — or a cross product for two 3-number vectors — with the working shown.⌁Graphing Calculator
Type a function. You get its graph on a grid, drawn point by point from the function itself.△Trig Calculator
Type an angle. You get sin, cos, tan and their reciprocals, in degrees or radians.½Fraction & Percent Calculator
Add, subtract, multiply or divide two fractions — or work a percentage. Steps include the common denominator and the cancelling, shown with the Euclidean algorithm.▥Statistics Calculator
Type a list of numbers. You get mean, median, mode, quartiles and standard deviation — plus combinations, permutations and normal-distribution probabilities.∿Fourier Series Calculator
Partial sums of the classic waveforms — square, sawtooth, triangle, parabola — with closed-form coefficients, the first coefficients listed, and the error at your x measured against the true function. Gibbs overshoot included, not hidden.✒Fourier Drawing — Epicycles
Two chains of rotating arms — one for x(t), one for y(t) — draw a knight, a bat, a heart, a star and more, live. Slide N from 1 to 50 harmonics per axis and watch detail arrive, with the mean error printed as it falls.λEigenvalue & Eigenvector Calculator
Characteristic polynomial, eigenvalues and unit eigenvectors for 2×2 and 3×3 matrices — repeated roots reported honestly, complex pairs included, and every result checked against the trace and determinant identities.A²Matrix Properties Checker
Nilpotent, idempotent, involutory, orthogonal, symmetric, skew-symmetric — tested by actually multiplying the matrix out, with A² and the decisive power printed as the proof. Trace and determinant alongside.⚗Molar Mass Calculator
Type a chemical formula. You get its molar mass, element by element, from the standard atomic weights.🧪Dilution Calculator
C1V1 = C2V2. Fill in any three of concentration and volume, leave one empty, and get the fourth.pHpH Calculator
Turn a hydrogen-ion concentration into a pH, or a pH back into a concentration.➤Velocity Calculator
Distance and time in, speed out — with the multiply-back check.FForce Calculator
Newton's second law, F = m × a. Mass and acceleration in, force in newtons out.½mv²Kinetic Energy Calculator
KE = ½mv². Mass and speed in, energy in joules out.ΩOhm's Law Calculator
V = I × R. Fill in any two of voltage, current and resistance; leave one empty and get it.⌂Mortgage Calculator
Loan amount, interest rate and term in; monthly payment, total interest and a year-by-year balance out. The formula is shown, not hidden.≋Loan Calculator
Any loan — car, personal, student. Amount, rate and term in; monthly payment and total interest out.%Compound Interest Calculator
Starting amount, rate and years in; final value out, with the growth shown year by year. Optional monthly deposits.♥BMI Calculator
Weight and height in, BMI out, with the standard range it falls in. Metric or imperial.kcalCalorie Calculator
Daily calorie needs from the Mifflin–St Jeor formula — named, shown in numbers, and labelled an estimate, because it is one.40wPregnancy Due Date Calculator
First day of the last period in, estimated due date out — Naegele's rule, 280 days, shown plainly.$Tip Calculator
Bill and tip percentage in; tip, total and the per-person split out.y′Differential Equations Solver
The two starter equations, solved exactly: growth and decay (dy/dx = k·y) and approach-to-balance (dy/dx = a·y + b), with an initial value.◍Country Facts
Capital, population, area, density and currency for 48 countries — population labelled as the UN estimate it is, density calculated on the page, and a standalone page for every country.🍎Nutrition Calculator
Calories, protein, carbs, fat and fibre for 24 everyday foods — per 100 g from USDA reference data, scaled to any amount with the arithmetic shown.◉Age Calculator
Exact age in years, months and days, total days lived, the weekday of birth, and the countdown to the next birthday.📖History Timeline
27 anchor events from the Great Pyramid to the smartphone: pick any two and get the years between them and how long ago each was, with the counting shown.AaWord Counter
Words, characters, sentences and reading time for any text — counted in your browser; the text never leaves your device. The reading pace used is printed, not hidden.☎NATO Phonetic Alphabet Converter
Type a word, name or code and get it spelled in the NATO phonetic alphabet — Alfa, Bravo, Charlie — the alphabet built to be unmishearable.∴Number Base Converter
Binary, octal, decimal and hexadecimal, converted exactly (big-integer arithmetic, no floating-point drift), with the positional working shown.☾Moon Phase Calculator
The moon's phase, age and lit fraction for any date, from the standard 29.53059-day cycle — with the approximation labelled, because it is one.≋Richter Scale Calculator
Compare two magnitudes: how many times more shaking, and how many times more energy. The two answers are very different, and the page shows why.◆Density Calculator
Mass from volume, or volume from mass, for 19 materials with typical densities — water, steel, gold, oak, ice and more. 'Typical' is printed on the page, because alloys and woods vary.?Random Number Generator
Random numbers in any range, dice rolls and coin flips — drawn with the browser's cryptographic random generator, the same source your device uses for security tokens.▭Aspect Ratio Calculator
Simplify any width × height to its ratio (1920 × 1080 → 16:9), or find the missing side of a ratio. For screens, video, film and photos.🖥Screen Size Calculator
A '65-inch TV' is 65 inches corner to corner — this turns the diagonal into the real width and height, for TVs and monitors, with Pythagoras shown.🎟Lottery Odds Calculator
The exact jackpot odds of any pick-N-from-M lottery, bonus ball included — counted with combinations, not estimated. The number is bracing; that is the point.♠Playing Card Probability Calculator
Exact probabilities for drawing cards: aces in a poker hand, hearts in a draw, any target cards in any hand size — counted with combinations from a 52-card deck.🐠Aquarium Volume Calculator
Tank length × width × height in, litres and US gallons out — plus what the water alone will weigh, which your floor and stand care about.🖼Photo Print Size Calculator
How big can this photo print? Pixels and DPI in, print size out — plus the megapixels, and what dropping to 150 DPI does to size and sharpness.🌐Time Zone Converter
Convert any date and time between 17 cities, daylight saving handled by the same timezone database your phone uses — plus a live 'right now around the world' table.iComplex Number Calculator
Add, subtract, multiply and divide complex numbers, convert to polar form, and find all the nth roots — with the conjugate and De Moivre steps shown, not just answers.ΣTaylor Series Calculator
Taylor and Maclaurin expansions of sin, cos, eˣ, ln(1+x) and 1/(1−x) to any order up to 15 — every coefficient computed from the derivatives, and the truncation error measured against the true value.y″Second-Order Differential Equations
Solve y″ + py′ + qy = 0 with initial values — all three cases: distinct real roots, a repeated root, and complex roots with oscillation — via the characteristic equation, constants solved in front of you.▥Probability Distributions Calculator
Binomial, Poisson and normal probabilities — exact and cumulative — with the standardisation and the sums shown. The same functions that sit behind statistics tables, computed in the open.→3D Vector Calculator
Dot product, cross product, angle, lengths, projection and the scalar triple product for three-dimensional vectors — every component computed in the open, with the perpendicularity check built in.≡Modular Arithmetic Calculator
Modular inverses by the extended Euclidean algorithm, Euler's totient from the factorisation, linear congruences with every solution listed, and fast modular powers — number theory with the working shown.▦Matrix Rank & RREF Calculator
Reduced row echelon form and rank for whole-number matrices, computed in exact fractions — every row operation listed, no floating-point fog. The RREF is unique, so the answer can be checked by anyone.
Type an equation or a plain sum. You get the answer and every step, free — the steps other sites lock behind a subscription.∫Integral Calculator
Type a function. You get its indefinite integral and the rule used on every term.∂Derivative Calculator
Type a function. You get its derivative and the rule used on every term.limLimit Calculator
Type a function and the point it approaches. You get the limit and how it was found — by substitution when that works, from both sides when it does not.×Factor Calculator
Type a whole number or a quadratic. You get its factors and the divisions that found them.≡Simplify Calculator
Type an expression. You get its simplest form, and a same-value check at real numbers.⧉System of Equations Solver
Type two or three linear equations. You get the values that satisfy all of them at once, found with Cramer's rule.▦Matrix Calculator
Type a matrix. You get its determinant, inverse or eigenvalues — or a cross product for two 3-number vectors — with the working shown.⌁Graphing Calculator
Type a function. You get its graph on a grid, drawn point by point from the function itself.△Trig Calculator
Type an angle. You get sin, cos, tan and their reciprocals, in degrees or radians.½Fraction & Percent Calculator
Add, subtract, multiply or divide two fractions — or work a percentage. Steps include the common denominator and the cancelling, shown with the Euclidean algorithm.▥Statistics Calculator
Type a list of numbers. You get mean, median, mode, quartiles and standard deviation — plus combinations, permutations and normal-distribution probabilities.∿Fourier Series Calculator
Partial sums of the classic waveforms — square, sawtooth, triangle, parabola — with closed-form coefficients, the first coefficients listed, and the error at your x measured against the true function. Gibbs overshoot included, not hidden.✒Fourier Drawing — Epicycles
Two chains of rotating arms — one for x(t), one for y(t) — draw a knight, a bat, a heart, a star and more, live. Slide N from 1 to 50 harmonics per axis and watch detail arrive, with the mean error printed as it falls.λEigenvalue & Eigenvector Calculator
Characteristic polynomial, eigenvalues and unit eigenvectors for 2×2 and 3×3 matrices — repeated roots reported honestly, complex pairs included, and every result checked against the trace and determinant identities.A²Matrix Properties Checker
Nilpotent, idempotent, involutory, orthogonal, symmetric, skew-symmetric — tested by actually multiplying the matrix out, with A² and the decisive power printed as the proof. Trace and determinant alongside.⚗Molar Mass Calculator
Type a chemical formula. You get its molar mass, element by element, from the standard atomic weights.🧪Dilution Calculator
C1V1 = C2V2. Fill in any three of concentration and volume, leave one empty, and get the fourth.pHpH Calculator
Turn a hydrogen-ion concentration into a pH, or a pH back into a concentration.➤Velocity Calculator
Distance and time in, speed out — with the multiply-back check.FForce Calculator
Newton's second law, F = m × a. Mass and acceleration in, force in newtons out.½mv²Kinetic Energy Calculator
KE = ½mv². Mass and speed in, energy in joules out.ΩOhm's Law Calculator
V = I × R. Fill in any two of voltage, current and resistance; leave one empty and get it.⌂Mortgage Calculator
Loan amount, interest rate and term in; monthly payment, total interest and a year-by-year balance out. The formula is shown, not hidden.≋Loan Calculator
Any loan — car, personal, student. Amount, rate and term in; monthly payment and total interest out.%Compound Interest Calculator
Starting amount, rate and years in; final value out, with the growth shown year by year. Optional monthly deposits.♥BMI Calculator
Weight and height in, BMI out, with the standard range it falls in. Metric or imperial.kcalCalorie Calculator
Daily calorie needs from the Mifflin–St Jeor formula — named, shown in numbers, and labelled an estimate, because it is one.40wPregnancy Due Date Calculator
First day of the last period in, estimated due date out — Naegele's rule, 280 days, shown plainly.$Tip Calculator
Bill and tip percentage in; tip, total and the per-person split out.y′Differential Equations Solver
The two starter equations, solved exactly: growth and decay (dy/dx = k·y) and approach-to-balance (dy/dx = a·y + b), with an initial value.◍Country Facts
Capital, population, area, density and currency for 48 countries — population labelled as the UN estimate it is, density calculated on the page, and a standalone page for every country.🍎Nutrition Calculator
Calories, protein, carbs, fat and fibre for 24 everyday foods — per 100 g from USDA reference data, scaled to any amount with the arithmetic shown.◉Age Calculator
Exact age in years, months and days, total days lived, the weekday of birth, and the countdown to the next birthday.📖History Timeline
27 anchor events from the Great Pyramid to the smartphone: pick any two and get the years between them and how long ago each was, with the counting shown.AaWord Counter
Words, characters, sentences and reading time for any text — counted in your browser; the text never leaves your device. The reading pace used is printed, not hidden.☎NATO Phonetic Alphabet Converter
Type a word, name or code and get it spelled in the NATO phonetic alphabet — Alfa, Bravo, Charlie — the alphabet built to be unmishearable.∴Number Base Converter
Binary, octal, decimal and hexadecimal, converted exactly (big-integer arithmetic, no floating-point drift), with the positional working shown.☾Moon Phase Calculator
The moon's phase, age and lit fraction for any date, from the standard 29.53059-day cycle — with the approximation labelled, because it is one.≋Richter Scale Calculator
Compare two magnitudes: how many times more shaking, and how many times more energy. The two answers are very different, and the page shows why.◆Density Calculator
Mass from volume, or volume from mass, for 19 materials with typical densities — water, steel, gold, oak, ice and more. 'Typical' is printed on the page, because alloys and woods vary.?Random Number Generator
Random numbers in any range, dice rolls and coin flips — drawn with the browser's cryptographic random generator, the same source your device uses for security tokens.▭Aspect Ratio Calculator
Simplify any width × height to its ratio (1920 × 1080 → 16:9), or find the missing side of a ratio. For screens, video, film and photos.🖥Screen Size Calculator
A '65-inch TV' is 65 inches corner to corner — this turns the diagonal into the real width and height, for TVs and monitors, with Pythagoras shown.🎟Lottery Odds Calculator
The exact jackpot odds of any pick-N-from-M lottery, bonus ball included — counted with combinations, not estimated. The number is bracing; that is the point.♠Playing Card Probability Calculator
Exact probabilities for drawing cards: aces in a poker hand, hearts in a draw, any target cards in any hand size — counted with combinations from a 52-card deck.🐠Aquarium Volume Calculator
Tank length × width × height in, litres and US gallons out — plus what the water alone will weigh, which your floor and stand care about.🖼Photo Print Size Calculator
How big can this photo print? Pixels and DPI in, print size out — plus the megapixels, and what dropping to 150 DPI does to size and sharpness.🌐Time Zone Converter
Convert any date and time between 17 cities, daylight saving handled by the same timezone database your phone uses — plus a live 'right now around the world' table.iComplex Number Calculator
Add, subtract, multiply and divide complex numbers, convert to polar form, and find all the nth roots — with the conjugate and De Moivre steps shown, not just answers.ΣTaylor Series Calculator
Taylor and Maclaurin expansions of sin, cos, eˣ, ln(1+x) and 1/(1−x) to any order up to 15 — every coefficient computed from the derivatives, and the truncation error measured against the true value.y″Second-Order Differential Equations
Solve y″ + py′ + qy = 0 with initial values — all three cases: distinct real roots, a repeated root, and complex roots with oscillation — via the characteristic equation, constants solved in front of you.▥Probability Distributions Calculator
Binomial, Poisson and normal probabilities — exact and cumulative — with the standardisation and the sums shown. The same functions that sit behind statistics tables, computed in the open.→3D Vector Calculator
Dot product, cross product, angle, lengths, projection and the scalar triple product for three-dimensional vectors — every component computed in the open, with the perpendicularity check built in.≡Modular Arithmetic Calculator
Modular inverses by the extended Euclidean algorithm, Euler's totient from the factorisation, linear congruences with every solution listed, and fast modular powers — number theory with the working shown.▦Matrix Rank & RREF Calculator
Reduced row echelon form and rank for whole-number matrices, computed in exact fractions — every row operation listed, no floating-point fog. The RREF is unique, so the answer can be checked by anyone.